| OCR Text |
Show 374 DR. B. C. A. WINDLE AND MR. F. G. PARSONS ON THE [Apr. 6, surface of the platysma, and so reaches the angle of the mouth. In the Polecats (69, 70), where the head is a good deal elongated, this muscle, instead of coming all the way from the ear, rises from the anterior part of tbe zygoma just behind the orbicularis palpebrarum (see fig. 3, p. 375). As w e think it an advantage, wherever possible, to use the names familiar to human anatomists, w e shall speak of this as the levator anguli oris, though it only comes from the zygoma in certain cases. Tbe second muscle which is covered by Ihe platysma is the sterno-facialis or sphincter colli: this rises from the back of the root of the ear and meets its fellow of the opposite side in the mid-ventral line of the neck, covering in its course the parotid gland (see fig. 2, p. 375). In the Felidae this muscle is strongly marked Fig.l. Face-muscles of Lutra vulgaris. and the anterior part comes from the fascia over the masseter. In no case that w e have seen does it reach, as in the rodents, to the sternum1 (XLI.). The orbicularis palpebrarum is not very strongly marked, from its posterior edge two or three bundles of muscular fibres run backwards and act as retractors of the angle of the eye ; these are best seen in the Canidae. The levator labii superioris is always w^ell marked and passes from tbe anterior angle of the eye to the upper lip, deep to it is a plane of muscle acting on the nose. The orbicularis oris is well marked. The occipito-frontalis is a plane of fibres which covers the scalp; the lateral part of the frontalis is attached posteriorly to the ear and forms the anterior auricular muscle, while the lateral part of the occipitalis is attached anteriorly to the ear and is thickened to form the transversus nuchas ; deep to this are one or two posterior auricular muscles. It will thus be seen that the main muscles of the face are disposed in such a way as to draw the soft parts of the lips and nose clear of the teeth, and also to lay back the ears; the sphincter ' In Bathyergus the sterno-facialis and sphincter colli are coexistent (XLII.). |
